The goal of this project is the identification of heritable characteristics of ion transport which may distinguish individuals with a primary affective disorder from normal controls. A study of sodium potassium stimulated adenosine triphosphatase NA+-K+-ATPase), a cation transport enzyme has been completed and data is being analyzed. We have reported that Nak ATPase is a "state" but not a "trait" marker for affective illness. We find not that plasma cortisol is negatively correlated with Nak ATPase in patients with affective disorder. We are engaged in a collaborative program of research on the lithium erythrocyte/plasma ratio in euthymic patients. We previously confirmed that bipolar patients have higher ratios than controls. However, we have noted an extended effect of lithium treatment on the ratio and are doing further studies to delineate this variable.